The Contact Toxicity of Arsenic to Earthworms and Regulatory Effect of Selenium
To investigate the acute filter paper contact toxicity of heavy metal arsenic(As)to earthworms and the regulatory effect of selenium(Se),Eisenia fetida was exposed to two media(filter paper and soil)with different concentrations of Se,and then the acute toxicity test of As was conducted by filter paper contact method.The results showed that the half lethal concentrations(LC50)on E.fetida directly exposed to As(V)contaminated filter paper for 24 and 48 h were 31.33 and 12.30 pg/cm2,respectively.After a 6 h period of adaptation on wet filter paper with Se concentration of 0.5 pg/cm2,the LC50 of As on E.fetida were 30.20(24 h)and 15.85 μg/cm2(48 h),respectively.After adapting to soil with Se concentrations of 6 and 12 mg/kg for one week,the LC50 of As to earthworms were 34.67-35.48 μg/cm2(24 h)and 18.62-21.88 μg/cm2(48 h),respectively.In conclusion,the pre-exposure of earthworms in Se-containing filter paper and soil both stimulated the improvement of LC50 values at 48 h,indicating that Se can improve the ability of earthworms to tolerate As stress during short exposure periods.This study provides new research ideas and methods for alleviating heavy metal pollution stress on soil biota.
NETL
NSTL
万方数据
